The present invention relates to a swivel draw bar structure of a suitcase and, more particularly, to a fixing structure which can achieve positioning and locking effects after turned.
Along with continual prevalence of travel mood and growing frequency of international business, demand of using traveling suitcases becomes higher and higher. When walking and pulling a suitcase, the best usage is to pull it along an elevation angle of 45 degrees. However, because the height of each person differs, the structure of the suitcase needs to be designed to meet different requirements. A suitcase having a retractable draw bar is the best trap taken along with a traveler. Two-joint type or multiple-joint type draw bars have been widely used in the structure of suitcases, wherein the two-joint type draw bars are more generally used. When the upper joint tube of a two-joint type draw bar is pulled out, only the bottom end of the upper joint tube and the top end of the lower joint tube are positioned. Because the length of each pulled-out joint tube can not properly be matched to each user, and because much difference will exist in the arrangement of the draw bar according to the height of the suitcase, the best angle of usage can not be achieved for every user. FIGS. 8 and 9 show a prior art structure of a draw bar, wherein a swivel upper joint tube 14 is installed at the top end of a lower joint tube 11. The upper joint tube 14 is pivotally joined between a pair of auriform sheets 111 of the lower joint tube 11 via a projective middle sheet 141. A plurality of holes 142 are disposed on the bottom plane of the middle sheet 141 for receiving a fixing bead 113, which is disposed in a groove hole 112 at the top end of the lower joint tube 11 and stuck by a spring 114. The structure is like an axial fixing structure of an electric fan. The advantage is that the adjustment and positioning of the fixing bead is very easy. However, this structure has the disadvantage that the position of the fixing bead will easily move because of the pressing force on the fixing bead. Therefore, the fixing effect is not good.
The primary object of the present invention is to provide a swivel draw bar structure of a suitcase so that the draw bar can be properly turned to be applicable to different situations of usage. The present invention can be applied to two-wheeled or four-wheeled suitcases. The user can set the most suitable angle of usage when pulling the suitcase. Moreover, the draw bar can be exactly positioned at the selected position. The adjustment of position can be proceeded via the handle according to the protraction/retraction action of the draw bar. Additionally, other joint tubes can be received in the lowermost joint tube.
To achieve the above object, a fixing sleeve is installed at the top end of the lower joint tube of the draw bar. A projective arc plate is joined at the center of the top surface of the fixing sleeve. A plurality of teeth are formed on the top surface of the arc plate. A downward straight groove is formed on the top surface of the fixing sleeve. A slide sheet is inserted in the straight groove. The bottom end of the slide sheet is a bevel joined with a bevel of a retractable button so that the retractable button can slide in a transversal groove of the fixing sleeve. The projective part of the retractable button can penetrate through the transversal groove and protrude out of a hole of the fixing sleeve to be locked in a hole of the lower joint tube. A swivel sleeve seat is joined at the bottom end of the upper joint tube. A pair of auriform sheets having holes extend downwards from the swivel sleeve seat. The holes of the auriform sheets are joined with a central hole of the arc plate via a spindle. An upward longitudinal groove is formed on the bottom surface of the sleeve seat for insertion of a slide retaining element. The slide retaining element is connected to the swivel sleeve seat through pin connection. The top end of the slide retaining element is joined with a drive element to drive the slide retaining element to move upwards or downwards. A tooth part is formed on the bottom surface of the slide retaining element to mesh with the teeth of the arc plate. A retaining sheet extends from the bottom surface of the slide retaining element. The bottom end of the retaining sheet contacts with the top end of the slide sheet to push the retractable button to be positioned in the lower joint tube.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings, in which: